GM Owner Manuals - Buick

Fuel E85 (85% Ethanol)
The 8th digit of the Vehicle Identification Number (VIN)
shows the code letter or number that identifies the
vehicle’s engine. The VIN is at the top left of the
instrument panel. See Vehicle Identification Number
(VIN) on page 6-108.
If the vehicle has the 3.9L V6 engine (VIN Code M), you
can use either unleaded gasoline or ethanol fuel
containing up to 85% ethanol (E85). See Fuel on
page 6-5. In all other engines, use only the unleaded
gasoline described under Gasoline Octane on page 6-6.
Only vehicles that have the 3.9L V6 engine (VIN Code M)
can use 85% ethanol fuel (E85). We encourage the use
of E85 in vehicles that are designed to use it. The ethanol
in E85 is a “renewable” fuel, meaning it is made from
renewable sources such as corn and other crops.
Many service stations will not have an 85% ethanol
fuel (E85) pump available. The U.S. Department
of Energy has an alternative fuels website
(www.eere.energy.gov/afdc/infrastructure/locator.html)
that can help you find E85 fuel. Those stations that
do have E85 should have a label indicating ethanol
content. Do not use the fuel if the ethanol content
is greater than 85%.
At a minimum, E85 should meet ASTM Specification
D 5798. By definition, this means that fuel labeled E85
will have an ethanol content between 70% and 85%.
Filling the fuel tank with fuel mixtures that do not meet
ASTM specifications can affect driveability and could
cause the malfunction indicator lamp to come on.
6-8